ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 immunofixation urine test was positive. Bone marrow biopsy was inconclusive due to extensive sclerosis. The first lymph node biopsy showed hyperplastic changes with increased polyclonal plasma cells and PD-1 positive cells. Results: As the diagnosis of clonal lymphoproliferative disorder was not confirmed in the first biopsy, the clinical hypothesis of Castleman disease was raised and appropriate treatment was initi- ated. However, there was no improvement and cutaneous lesions and thrombocytopenia worsened. A skin biopsy was performed, showing diffuse infiltration of the dermis and subcutaneous tissue by apparently mature plasma cells with kappa light chain restric- tion. In view of this, PCR-based clonality test was required in prior lymph node biopsy material, which resulted positive for a clonal T-cell proliferation. By reviewing the subtle morphological features in the histopathology, the diagnosis of Angioimmunoblastic T-cell lymphoma was finally made. Conclusion: AITL generally causes a variety of immune dysfunctions, something that can mimic a number of other diseases and cause diagnostic delays. In addition, atypical and unusual manifestations reported in this case may contribute to inappropriate treatments. Further studies are necessary to clarify the interplay between this lymphoma and plasma cell proliferations in order to prevent misdiagnosis. A detailed clinical evaluation and auxiliary tests, such as PCR-based clonality, are essential for precise diagnosis and must be available in medical practice. E-PS-11 | E-Posters Head & Neck Pathology E-PS-11-001 Νasal glomangiomyoma M. Givannakis, D. Anestakis*, G. Tsiropoulos, I. Dimitriadis, C. Charalampidis, P. Karkos *Laboratory of Pathology, Forensic Service of Thessaloniki, Greece Background & objectives: Glomangiomyoma is a histological vari- ant of glomus tumour. These are benign tumours, typically located in the subcutis or deep dermis of the subungual region of the fingers. We describe the clinico-pathological, immunohistochemical findings of a case of nasal glomangiomyoma. Methods: A 63-year-old man presented with a 2-month history of intermittent epistaxis and partial nasal obstruction with a dura- tion of two months. Posterior rhinoscopy revealed the presence of a nodule, less than 1 cm in diameter, in the left posterior nasal cavity, based in the middle turbinate and protruding in the middle meatus. The lesion was endoscopically excised, with macroscopi- cally clear margins. Results: The excised material was a round nodule with diameter 9 mm. Histopathology showed that the tumour was characteristically composed of solid sheets and cords of uniform cells with pale or eosinophilic cytoplasms and round or ovoid nuclei, compatible with glomus cells, interrupted by variable sized vessels. In a central area of the tumour, spindled cells with elongated nuclei and bipolar eosinophilic cytoplasm resembling smooth muscle differentiation were present. The immunoreaction of tumour cells, positive for smooth muscle actin and negative for CD34, that was positive in blood vessels, supported the diagnosis. It was suggestive of glomangiomyoma. Nuclear pleomorphism, mitoses and necroses were absent. Conclusion: Glomangiomyoma shows variable proportions of glo- mus cells, vascular structures, and smooth muscle cells. The most common site is the hand, particularly the fingers. Nasal glomangio- myomas are extremely rare. This may suggest that the histological type may be more important in predicting the clinical presentation than the anatomical location of the tumour. Despite being a rare entity, it should be included in the differential diagnosis in patients with common rhinological symptoms. E-PS-11-002 Primary intraosseous spindle cell carcinoma of the jaw bones: Is it a new histological entity? K. Kusafuka*, M. Fukushima, S. Baba, M. Suzuki *Shizuoka General Hospital, Japan Background & objectives: Intragnathic carcinomas mainly consist of primary intraosseous squamous cell carcinoma, central mucoepider- moid carcinoma and ameloblastic carcinoma, whereas they are very rare. We reported two extremely rare cases of primary intraosseous spindle cell carcinoma (PIOSpCC), clinico-pathologically. Methods: We selected intragnathic epithelial neoplasms from a pathology file of our institutions, selected intraosseous spindle cell carcinoma of jaw bones, and examined them, clinically, histologi- cally and immunohistochemically. Results: Two cases (0.4%) were selected: Case 1 was 43-year-old male with the swelling of the left mandible. Case 2 was 42-year- old male with the painful swelling of the right maxilla. Both showed the smoothly-surfaced masses, where the main tumours existed in the jaw bones with osteolytic destruction. Both showed the fascicular proliferation of atypical spindle cells. In case 1, the small nests of epithelioid cells were focally seen, whereas case 2 showed necrosis and multinucleated giant cells. Both were dif- fusely immuno-positive for pan-CK and vimentin. In case 2, spin- dle cells were focally desmin, but negative for myogenin. Ki-67 labelling index was 38% and 72%, respectively. Case 2 died of disease. Conclusion: We diagnosed both cases as PIOSpCC. PIOSpCC har- boured neither squamous cell carcinoma component nor amelo- blastic component. The worse prognosis of PIOSpCC is related to necrosis and high Ki-67 labelling index. Case 2 showed focal positivity for desmin, but was negative for other myogenic markers. Therefore, it was not intraosseous rhabdomyosarcoma of the jaw bones. We propose that PIOSpCC is an extremely rare but a new entity of primary intraosseous carcinoma. E-PS-11-003 Nasopharyngeal hairy polyp: a rare case report J. Madeira*, A. Alves, R. Almeida, M.R. Silva, M.A. Cipriano *Centro Hospitalar e Universitário, Portugal Background & objectives: Hairy polyps are rare developmental mal- formations mostly occurring in infants and neonates arising in naso- pharynx or oropharynx. They have a higher female incidence (6F:1M) with a left side predilection. Airway obstruction can be lethal and should be managed carefully. Methods: We report a case of a female neonate presenting a severe obstruction of the oropharynx with epistaxis and feeding difficulties. It was caused by a large mass that extends from the most posterior portion of the right nasal cavity to the aryepiglottic folds. The MRI documented an elongated heterogeneous lesion measuring 33x9x8mm, virtually occupying the entire lumen of the oropharynx. Results: Simple surgical excision of the mass was performed. Gross examination showed a gray pear-shaped pedunculated mass bearing few hair shafts. Histologic evaluation revealed a poly- poid lesion, composed of ectodermal and mesodermal elements, namely adnexal structures, adipose tissue and cartilage, covered S279